Rotor blades for wind turbines are made by laying a fibre material on a mould surface resembling a negative image of the fibre reinforced structure to be produced and in which a resin is infused and cured after the fibre material is laid on the mould surface. The form of such a blade is that is has a suction side and a pressure side with a shape determined by aerodynamical requirements. In a typical blade construction both sides are held in relation to each other by a beam, a spar or a web. Normally the web is casted or produced as a separate piece and afterwards being established together with other laid parts such as by using adhesives. As an alternative it is known that the web can be an integral part of a moulded structure and casted together with e.g. one or both of the sides of the blade. Basically the web is a structure which extends substantially perpendicular to the sides of the blades, therefore it is a challenge to build these parts together in a mould.
It is a known method to layout and build the web on a location remote to the blade moulds and subsequently lift and place the web in position in the mould so as to form the structure for being casted. This conventional method is shown in FIGS. 1 to 3.
FIG. 1 shows a blade mould 1 in which a glass fibre material 2 is laid out as a first side. FIG. 2 shows a vertical web construction 3 on which glass fibre material 4 is applied at a position remote from the blade mould 1. After building the vertical web construction 3 with said glass fibre material 4 the web construction 3 is lifted and positioned on the glass fibre material 2 in the blade mould 1 as is shown in FIG. 3.
FIG. 4 is a perspective view of the vertical web construction 3 of FIG. 2 whereby the vertical web construction 3 is made from wood and a plurality of glass fibre mats 5 is applied and laid on the vertical surface.
However, this conventional method is time consuming and requires much production facility space, as space is required for both the blade moulds and for the construction of the web.